It made headlines around the world, saw thousands of sightseers flock to see excavations and led to calls for Colchester to be named a world heritage site.

However, the discovery of the town's now globally-renowned chariot-racing arena - exclusively revealed by the Gazette in January 2005 - began in an undramatic style.

It was way back in 2000 that unusual Roman foundations were noticed as workmen dug a trench for electric cables near the football pitch in the north-west corner of Abbey Field.

The finds were carefully noted, but observers from Colchester Archaeological Trust had no idea of the huge significance they would take on.

Two years later, during work commissioned by developer Taylor Woodrow, digs in a paddock near Cavalry Barracks uncovered more odd remains.

Again, too little was exposed for any conclusions. After a series of larger discoveries in 2004, the penny dropped: the Trust's experts were looking at what was left of Colchester's own 15,000-seater Roman chariot-racing arena.

Now, seven years on, every key feature of the stadium can be pointed to on a map of modern Colchester.

We'll start at the beginning.

In the garden outside the former sergeant's mess, beside the access road leading to Cavalry Barracks, stood the starting gates where Roman stallions once snorted and scraped the earth as they waited for the race to commence.

Twelve gates, built barely big enough to squeeze in each charioteer, chariot and his team of four horses, stood either side of the circus's western entrance.

Above that, in a covered box, sat the city magistrates whose role was to get each race under way.

Remains of this little room have been easy to spot at the Colchester dig as the walls were intricately decorated, providing luxury in contrast to the cramped conditions below.

The chief magistrate would signal the start of each contest to the crowd by releasing a handkerchief from the window of the box, before a colleague pulled a lever to release the shutters of each gate.

Off the teams of horses would charge, jockeying to get the best position before they reached the "spina" that ran down the middle of the 940-metre circuit.

This central barrier, which confined them to a space just a few metres wide, had its halfway point beneath the junction of Circular Road North, Napier Road, Circular Road East and Flagstaff Road.

Here, digs uncovered the foundations of a monument - probably an Egyptian-style obelisk - the discovery of which adds weight to claims the circus was no mere horsetrack but the Ascot or Aintree of its day.

The horses turned at the halfway-point of each lap in the space between the end of the spina, whose curve is marked by a surviving section of St John's Abbey wall off Napier Road, and the east end of the arena, a few metres farther towards Mersea Road.

Those that survived the hairpin bend then galloped back down the other side of the spina to turn again at the opposite end, marking the completion of the first lap. Each of seven laps was counted down by an elaborate mechanism, that made a stone egg drop to the ground and pushed a carved dolphin into a new position.

The excavations show water was piped to the spina - and experts believe the dolphins might have been designed to spout a jet of water as they tilted forward.

Perhaps the most fascinating find of all came as the archaeological trust studied the area next to the turning post where each new lap began.

Even after hundreds of years underground, it is still possible to make out where the track was worn as the charioteers hugged the line of the spina to scorch round.

The archaeological trust hopes to unpick more fascinating details of what a day at the races would have meant.

But director Philip Crummy agreed his staff had documented "all the main elements that made up a Roman circus".

"We can still improve our knowledge but we have been able to account for all the different bits you would expect to find," he said, adding that developer Taylor Woodrow deserved credit for assisting the works.

"They even brought in a specialist team to lay drains by tunnelling underneath it," he said. "I think they've achieved a good outcome in the circumstances."

The hallowed spot where the dolphins spouted has already disappeared, be-neath a relaid Circular Road North.

Taylor Woodrow has agreed not to build homes anywhere within ten metres of the site.

It remains to be seen how the developer can work with Colchester Council to ensure the memory of the find is kept alive for future generations.