Building an above-ground fortress is demanding. Building a secure above-ground fortress without cheap traps is difficult. Building an above-ground fortress secured against zombie gorillas, skeletal fish and quite-alive-thank-you-very-much orcs should be something worthy of a community fortress.
Here is my proposed site:
Game: DF with Dig Deeper
Embark zone: Volcano, Tropical Moist Broadleaf Forest, Tropical Ocean, all sinister
Guidelines: Above-ground construction encouraged, sealing the fortress forbidden, trivial traps (stone fall, weapon, cage) strongly discouraged, mass trading of stone objects discouraged
Feel free to claim and equip a dwarf, claim a succession slot or both.