So the campaign I have in mind requires the party to constantly be moving around, and exploring different ruins of ancient civilizations. I've got a multitude of different ideas, but need more seeing as I plan on letting the party have some say in which ones they decide to venture out and explore, and often have the choices be layered in tiers of difficulty based upon setting and so on. HIT ME WITH YOUR BEST RUINS!
Ok, so few ideas that I have already come out with...
1. First ruins, pretty old, moist, nothing too suspicious till players locate back room used for rituals. They find an immortal man there, and on a high roll, may find a magical device that shows the happenings of before.
2. Mining town with three half-brothers, vying over the rights to mine, as well as access to the ruins. The ruins themselves are of dwarven origin, and show signs of preparing for war. It hasn’t held up too well from the excavations around it.
3. Goblins have recently taken residence in the newly found ruins, led by a Barghest, they have been harassing the nearby towns, making it easy to locate. The ruins themselves seem to be of Halfling origins.
4. Ruins located slightly under water off the coast. The majority of the city is completely underwater, and appears to have belonged to merfolk. Signs of magical protection sigils are abundant.
5. Ruins located in the far south jungles, a tyrannosaurus has made residence of the place. The residence of the ancient city appeared to have been attempting to make ritualistic sacrifices to thwart the coming storm.
6. Ruins located in a swamp. The ruins were originally floating, powered by magic. Due to no one operating, crashed into the lake below, which eventually became the swamp. Now harbors a black dragon.
7. Ruins protected by an elven group. They state that it is holy ground to them, but the true reasoning is that they had cut a deal with a green dragon not to bother it within its territory.
8.Dwarven city built directly over an ioun stone quarry. They had begun construction on war golems powered by the ioun stones. It is surprisingly in pristine condition.
9. Gnomish city completely booby trapped, almost no living things remain in it, although many spirits linger. The booby traps have been set up to completely and utterly non-stop damage the Terasque from emerging once more.
This list so far is from lowest level to highest level in terms of content ideas. I still need 7 more ideas, most of which are closer to the higher end, and two more for the lower end.
Just off the top of my head here:
Isolated ruins of an ancient civilization in the jungle who created wax golems of their greatest minds who believe they're the originals
Site of a siege between elves and hobgoblins who reanimate to resume the war every night, the 600+ year old elf locked in the dungeon probably knows why
A strange-temporally distorted citadel where the players encounter alternate versions of themselves all vying for the same artifact
Aside from that, do what the others suggested and just rip off anything you think might work, and just change one or two details and make it unique. For instance, I once ran a session where I ripped off the plot of James Bond Live and Let Die and just made the villains lizardfolk
Here is a ruin that I used at the beginning of my current campaign. It's in a desert.
Architecturally, the ruins emphasize curves, with half-ovals of stone overlaying other half-ovals in a circling pattern being seen as a general motif. Structures bend above the ground and down into it; entrances look like waves forming from the sand. Long, thin pillars support rooms and taller structures, with thick, smooth masonry along the sides of tunnels, chiseled into hexagonal patterns. Most of the temple is not visible above ground, although a large dome surrounded by broken walls and fragments lies at the center of the temple. To get inside the dome, one must travel through a curving network of tunnels and above-ground hallways. These tunnels are very difficult to navigate, with pathways crisscrossing constantly. Some have degraded exceedingly, letting all manner of creatures in…
I used giant desert scorpions. They tried to hide in a room with a broken ceiling. Another room had seven humanoid statues in various states of dilapidation along a back wall, and a throne lay in the center of the room. Four raised, large hexagonal tiles were lined up about 5 feet apart in front of it, and a crypt guardian defended the room. Some holes in the domed ceiling let light in, but if a person stepped on a raised tile out of tandem with the others an acid arrow trap would activate.
The center of the temple was a massive dome with broken pillars and piles of rubble strewn about. An at least 30 x 30 raised area of sorts contained a semicircle of pillars of varying heights.
I am not sure if this level of detail is what you wanted, but I digress. I like your ideas, they may just show up in my campaign soon.
E: This "temple" was actually a cover up for a massive arcane research facility for drow thousands of years ago. Well, the god they were researching was arcane energy incarnate, so maybe they weren't lying?