The Khamis Mosque, located in the village of Khamis just south of Jidd Hafs, is widely considered the oldest mosque in Bahrain and one of the oldest in the Arabian Gulf. The current structure is largely medieval but stands on foundations that may date to the late 7th century. Two minarets flank the prayer hall, each built in a different century — the asymmetry is visible and oddly charming.
The mosque is no longer in active use as a place of worship and is maintained as a historical site. Visitors can enter the compound and walk around the exterior. The setting — palms, old stone, a quiet residential street — is more evocative than any of the modern religious sites in Bahrain. It is about 10 minutes' drive from central Jidd Hafs.
Dress modestly if you visit. There is no admission fee. It is an easy stop on the way to or from Manama.