This area was the courtyard of a legionary building in the centre of the main fortress with a well dug by the ninth Hispanic legion in the middle of the 1st Century. The well was later incorporated into the Forum when Lincoln became a Colonia.
When excavated the well was found to be nearly 15m deep - it had a stone wellhead and was covered by four arches constructed from tile.
Today the well is covered in glass to protect it but you can still see these substantial structures along with small parts of the Forum walls. The well continued in use until the 17th Century.