In 1999, during the excavation of Seahenge, a second circle was discovered on Holme Beach. Named Holme II, this circle was found about 100 metres away from the original site. The second circle was much bigger measuring 13.2m (43ft) in diameter. It had a central setting of two oak logs, posts and a wickerwork fence with outer palisade surrounding it. Archaeologists dated the second structure to 2049BC, the exact date as Seahenge. This is the only known case in British pre-history where two monuments were built at exactly the same time.
The second structure was studied by archaeologists, but the decision was made not to excavate. Holme beach is located within a very sensitive nature reserve that is home to internationally important populations of migratory birds. These are easily disturbed by people. No archaeological remains can be seen at the site today.