1. There are four Roman practice camps at Llyn Hiraethlyn, one of which is possibly unfinished.
RCAHMW, April 2009

2. The remains compromise earthen banks and ditches with well-defined central entrances and associated tituli or entrance sheilding ditches. The practice camps were probably constructed by auxiliary soldiers from the primary fort at Tomen-y-Mur.
Source: Cadw scheduling description, October 2009