Ruins of Adventure is a tie-in module based on an old computer rpg called Advanced Dungeons & Dragons: The Pool of Radiance, a game that was somewhat popular for its time. The module was released at the same time as the video game as a cross promotion, the idea being "you liked the video game, now run it with your game group" and vice versa.
The module follows the plot of the video game pretty well: the adventure party have come to the city of Phlan, which is mostly occupied with monsters controlled by some unknown enemy. Starting from the civilized area (which is more fleshed out in more detail, but does not have a map), the group performs various tasks for the ruling council of the civilized areas, clearing out the blocks one by one, until you finally face the enigmatic master of the forces that conquered Phlan so many years ago.
While the adventure is very well done, there are a few things that make the game a little less engaging than it could be. First, the slums and mansions sections have been changed from the video game so that there are no planned encounters. This was probably done to avoid spoilers in the computer game, but these areas, which were important sections of the game, have been reduced to "wander around and fight monsters until the GM is bored and then you're done." You may want to find a few FAQs and walkthroughs of the computer game and place the encounters back in as best you can in the changed maps.
Second, and this actually is a problem, the wilderness map has a player map, but instead of a DM map, there is a second player map. DMs looking for locations for the DM map will have to do an internet search for the DM map or just guess where everything is from the descriptions in the module.
Other than the problems mentioned, I highly recommend this module, and it's sister module "Curse of the Azure Bonds." They tell an interesting story worth exploring.