Monumentum Altar of Inveresk with a griffin This second altar discovered to date near Inveresk includes several elements unusual in Mithraic worship. PublishedThe New Mithraeum29 Jan 2022 Inveresk altar with griffin.AOC Archaeology Group The full article is reserved for our members. Log in or create a free account to access the entire site. Local sandstone altar found in 2010 in what must have been a wooden Mithraeum built in the middle of a field, not far from the fort of Inveresk, near the Antonine Wall. It was carefully laid face down next to another altar of the same construction dedicated to Sol.