I only know of one that has been somewhat abandoned in recent years. The Tharys Ancestral Tomb is just northeast of Seyda Neen. There are tombs closer to Vivec, but the Dunmer might take offense at your explorations.

The Dunmer bury their dead in such tombs. It is best to avoid offending the Dunmer by entering them. There are rules to govern such things, but I do not fully understand them.