After publicising for information regarding the Basin Mound in the Sailing club field, a variety of suggestions have been forwarded to me including a visit or two by people in the Maldon area. Unfortunately no one has any solid evidence so far as to the origin or possible usage over the years other than having an Anderson shelter built into it during the Second World War.

So far the speculation has all been based around the possible solutions already listed on this page, no new or earth shattering answers as to when or what the Basin Mound was. I had an interesting email from a Viking descendant pointing me towards his web site, the reason it is interesting is that the Battle of Maldon is looked at from the Vikings point of view and suggests the battle was in fact an ambush by the British on the Vikings who were coming to collect their ransom. "The 'Danes' (a generic expression about all Scandinavians at that time) were supposedly so injured that they barely could man their ships, but the exaggeration in this stands towards another version of the Chronicle for that year, which merely states that the Danes afterwards collected their ransom. Undoubtedly this was also why they came, so this statement stands in great contrast to what must have happened. Nonetheless, even the Vikings must have had great losses and injured and, in fact, the Norse sagas also speaks about a injury which almost killed Olaf. That story is however not speaking of a certain battle, but rather of an ambush which may turn out to have been this battle near Maldon. Olaf had to be carried away on his shield afterwards and almost died according to the sagas."

The site is worth a visit to get the full sequence of events and you can then understand their comment of: "At the risk of gaining the Brit's anger, we believe the story of English bravery is exaggerated beyond the recognizable"

The contact concerned also stated that only senior Vikings from a battle would be cremated, then placed in a mound near the battlesite, this would mean it is unlikely 3 burial mounds would be made from the Viking point of view.

• The Vikings asked if they could come onto the dry shore and form up properly, and the Anglo-Saxon leader, being a proper gentleman, let them. It must have looked good on his tombstone.
• The tide went out. Then Byrhtnoth died of sportsmanship. Maybe that's why his name has kind of gone out of fashion.
• Oh dear. If ever there was a supreme example of British "fair play"; and their tendency to snatch defeat from the jaws of victory, this is it. Basically, once the Brits had got their formidable Viking foe in a genuinely losing position on what could only be described as a VERY sticky wicket, they then allowed their very determined opposition to change the rules of the game against the Britons and in the Vikings’ favour. Full-time score: Vikings 1, Britain 0. Perhaps this is where the English cricket team first originated...
• They had a deep and meaningful discussion on the relative merits of Volvos and Vauxhalls. Volvos won. Quite right too.
• A police car drove up and they were all arrested.
• It happened that Englishmen invented the cavalry (and discovered that it does not pay). "Poor Vikings!" said a couple of british heros "if they have to walk against us in that little tongue of land, when the tide goes down, they'll arrive here wet and columned, [what kind of columny is this?] and we can kill them too easily.... Let them arrive dry and strong, let them draw up against us, and then we can fight an honest battle". So they honestly did. So the Vikings honestly slaughtered them.
• All the misinformed souls who thought Vikings had horns on their helmets were in for a bit of a surprise. Apparently they convinced the government to raise a very high tax - to buy off the invaders.
• A "stare-down" ensued until both sides became tired and went home.
• Determining that neither group had a claim to the island, they agreed to sit down and share a cup of ale. [How civilised. Landlord - a flagon of your best beer please! And 278 straws.]
• Everything else happened next ... up to and including right now!
• Facing each other across a muddy riverbed, the Vikings asked to be let up on dry land so they could have a fair fight. The English leader, Byrhtnoth, felt very confident and agreed. Battle on dry land ensued and Byrhtnoth was killed. Someone made a poem about it, reminding us to answer "No!" when someone wants to kill us and asks for a fair fight!
• Gen. Brightnot, a typical army man fresh from the playing fields of Eton, yelled out "Red Rover, Red Rover, send all of your homicidal maniacs rightover". When the H.M.s arrived, the farmers held their own until someone stole a horse, and some of the farmers said, "The hell with it, my cows need milking" and left. The others didn't last long. Brightnot's last words were, "Well played, boys!"
• In essence, the resident Anglo-Saxon army was defeated by their leader, Byrhtnoth. Early on, it became apparent that even at low tide, the causeway the Vikings had to cross was so narrow they could be held back by a mere three capable defenders. The Vikings asked that they be allowed to cross unmolested, so they could fight properly, on equal terms. Amazingly, Byrhtnoth agreed to this. He was killed in the ensuing battle. The Vikings won this fight, and continued their tour of England.
• Karl of Snoz engaged the Vikings in witty banter until the tide came in and drowned the invading horde.
• Not much battle could be had on the causeway, so the Vikings asked if they could fight like men on the mainland. The Anglo-Saxon chief said "Sure". Bad move.
• Raping and Pillaging? [No need to ask]
• Shot in the dark: They waded into the water and shot each other with arrows. The corpses piled up and formed a bridge across the water. Then the fight continued as a melee. I have a grisly mind. [At least this last statement is true]
• The brave but stupid Byrhtnoth and his thegns fought like mad, Byrhtnoth was slain, his men battled on until Colin Powell and the US Special Forces landed, took control of the sector, and routed the overly testosteroned Vikings. Powell set up a council of warlords and divided Northey Island into three parts: Big Northey, Little Northey and Medium Northey. Today it's a vacation mecca for large bearded men.
• The leader of the Saxon forces gave a speech about how they were going to fight to the last man, and damned if they didn't.
• The narrow channel of water disappeared, becoming a swampy causeway, as the tide went out. After a lot of shouting across the remaining mud and bog, the two sides joined in battle. The handful of Anglo Saxons had a strong advantage on their dry ground, compared to the Viking hordes who were bogged down in the black marshes. The Vikings asked for a fair fight on solid ground (what's fair about 3,000 or so Vikings vs a couple of hundred Anglo Saxons?) and the leader of the Anglo Saxons, Byrhtnoth, Earl of Essex, somewhat unwisely agreed..... a decision which ultimately cost him and his pals their lives, after a brave fight. The Vikings were then free to introduce words like "smorgasbord" into the English vocabulary.
• The Norsemen complained about the condition of the pitch ("too narrow"), so the fair-minded Anglos invited the Vikes to c'mon over and have a game of footy on a real pitch, but since the Vikes had a Swedish coach and the Anglos didn't, the Anglos were routed.
• The tide came in, the tide went out, the Vikings gathered round and they all began to shout: "Hey, Hey, Uncle Dud, It's great to beat your feet in the Maldonsippi mud."
• The tide went out, exposed causeway, vikings ran across to attack, were met by three anglo-saxon men, conned king of anglo-saxons to let on to dry land to fight, death of king, terrible poem of heroics written.
• The tide went out. Or maybe it came in. But the Vikings asked permission to cross to the mainland and before they could start to cross, they were eaten by a huge shark. Later this event was made into a film called "Jaws."
• The Viking's asked permission to cross to the mainland. The Saxon commander, wanting a clear divinely ordained victory, gave them permission. The Saxons were promptly slaughtered.
• The Vikings catapulted towels across the channel, thereby booking all the best spots on the beach. [Beach? I swam at Maldon in my childhood. At low tide there are 2 miles of mud flats]
• The vikings decided it wasn't sporting to fight your way across a narrow causeway surrounded by mud. They would've have been at a distinct disadvantage. They asked for, and received, permission to cross and start the battle from a more advantageous position. The stupid (and I use the term advisedly) Anglos didn't want to look wimpy. Of course the Anglos were slaughtered.
• The Vikings got stalled a bit because the tide was rising. Then Brithnoth (the Anglo Saxon leader) was dumb enough to allow the big scary brutes onto land when the tide ebbed. The Brits lost, a poem was written and 1000 years later the place become National Trust and a bird sanctuary.
• The Vikings opened up a can of Whoop-ass and belted the Anglo-saxons. Byrhtnoth, Earl of Essex, was killed and the rest of the Anglo-Saxons did a runner.
• The vikings, unable to fight their way across the causeway linking the island to the beach (held by only three men, a la Horatius), asked that Brythnoth, Earl of Essex, the English commander, permit them to cross and then fight them on the landward side. Brythnoth, being as intelligent as the average English aristocrat, allowed this. He was killed and his men slaughtered. Typical titled sheep-wit.
• They all died a slow horrible painful untimely due but not necessarily fateful death. [Is there a kind of death that is not fateful?]
• They had to run away from the smell. Oh, DREW up, right. The Anglo-Saxons fought fair and lost.
• They negotiated a collective, opening a 'for profit' saltworks and spa. (This answer is for Victorians only, I fear).
• They set up a game of beach cricket. The village opened the batting and suffered a terrible batting collapse and were routed. Once the captain was out for a duck the rest followed quickly. All out before tea. Then the fielding was a shambles and the bowling, all over the shop. The visitors scored freely. It was a walk over (the water). Very embarrassment as the Vikings are not known as a cricketing nation.
• They transported their boats across the island and went out the other side. I saw the re-enactment on the TV show 'Secrets of the Ancients". [Nearly right]

You just told us the answer in the question. The Battle of Maldon.