Well of Souls (thing)

Two SF series by Jack Chalker, focusing on the Well-World, a weird planet divided into hundreds of distinct little biospheres each having its own distinct climate, races, and techonology levels.

First series:

• Midnight at the Well of Souls
• Exiles at the Well of Souls
• Quest for the Well of Souls
• The Return of Nathan Brazil
• Twilight at the Well of Souls

Second Series (called The Watchers at the Well):

• Echoes of the Well of Souls
• Shadow of the Well of Souls
• Gods of the Well of Souls