Dwellers
This was the second official mod I ever owned.
I DM'd it many years ago, probably as a first edition game/group. Getting into the city was fun as that part had been used as a tournament mod, if I recall correctly. Once in the city things bogged down as there were only so many set encounter areas. The rest were random encounters, but only so many times the party could be entertained meeting two apes.
The city, ruins really, put tremendous demands on my desceptive talents. Well, it wore them out so I resorted to putting the map open on the table and they could wander to the lettered areas.
I do recall the excitement of the 'fight' between the party's ranger and the chief of the tribal people. The ranger was lawful good so he had to fight fair, while the chief could fight dirty. Still, the ranger won and became their 'chief.' As they wandered the ruins some more, they would often encounter other members of the tribe who would want to embrace him.
Then there was the mage, Horan. In truth, there is no good or valid reason for them to simply invade his house and kill him. But, don't all party's feel the need to do so? Mine did. But, Horan, whose name they never got, escaped. Since I had placed this in Greyhawk in Hempmonoland [sp?], I had him flee to other jungle areas. Years later when I started to develop my own cities, I had him emerge in Fort Thunder in the Amedio Jungle. Some of the same PCs encountered him, now as an upstanding citizen who they did not realize they once wanted to kill.
I did use the entry/exit part with other groups, just as jungle adventures, but never used the ruins again.