The ancient archway
An archway was a passage decorated with a structure at the entrance.
The catacombs beneath the monastery at P'Jem featured archways. One of these led to the reliquary. It was decorated with Vulcan symbols. (ENT: "The Andorian Incident")
The art department section on the call sheet of the episode is listing it as a "large ornate archway". The writings on this archway are based on the Vulcan writings seen on Spock's robe in Star Trek II: The Wrath of Khan. ("The Andorian Incident", text commentary, ENT Season 1 DVD special feature)
Blueprints for this set were later sold off on the It's A Wrap! sale and auction on eBay. [1]