Within the last few years I read a story on-line that had mass-transmitter arches with an altar form.
Earth is near the technology level we currently have.
Our hero warrior is fighting the bad guys in a Indiana Jones or spy novel way, ducks into a cave in
some kind of wild and desolate place, jumps through the portal and is evaluated by some kind of
automated system that determines he only has access to one or more places, enhances his body to
survive there and sends him there.
The place he is sent has several dragons in places of power. When he passes their tests he is given
an artifact of great power. One place is a desert with a pyramid. One place is an ice fortress with
Nordic fighters and valkyries. One place is an island in a sea.
Through many travails he finds new and old friends.
I have forgotten the story name and the author.
I just realized it may have had more episodes in the series so wanted to catch up
by JawitK