Can't remember title of SF Novel series

I was reading about Riverworld and was reminded of another created world where there were thousands of hexagonal regions all with very different biomes and intelligent inhabitants.

I can’t for the life of me remember the name of this novel or if it was a series of novels.

Could someone help out this somewhat absent-minded just barely middle-aged SF fan?

That’s Jack Chalker’s Well of Souls series, featuring Nathan Brazil and Mavra Chang.

ETA: sorry for the delay in answering!

Jack Chalker “Well of Souls” series

(eta: I answer in three minutes and someone’s beaten me!)

Beaten again, by two people!

Thank you all for the rapid replies.

This is such a GREAT forum!

Added value post.

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
The Sea is Full of Stars
Ghost of the Well of Souls

Also:

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

An important note. After the first 4 novels, Chalker said he was done with the Well of Souls, someone would have to give him $1 million dollars to write another one. It took a few years, but someone did. I have not tried any of them after the first 4, since the quality was going down hill at that point, IMO.

I also bailed after 3 or 4 IIRC. It had a great start, though.