The York Museum Gardens sport this ancient tower, the only one standing of the eight towers built by the Romans at each end of their walls. This one may be the work of Constantine the Great but more likely was built a century before his time. While the Romans started with a small fort not much larger than the Minster area, by 300 AD the town had grown (and the natives had grown so restless) that they encircled a much larger area.
The ten-sided multangular tower is Roman for the bottom 2/3s. Note the red horizontal lines that mark the tiles the Romans used to tie the inner and outer walls together. They used rectangular stones, called saxa quadrata. The larger stones were added during the middle ages including the archery slots.
The tower inside contains a few Roman sarcophagi. Originally it had a roof and three separate floors.