Mysterious Shrines are unique objects which provide your team an additional skill point or some amount of experience points. They can be found during your travels with a high Perception skill and some people can also share with you their knowledge about Shrines' location if you will do something good for them, mostly outside of the quests, In other cases you can also find a Shrines' location by using a specific computer.
Shrines are also located in almost every important location such as Highpool or The Prison. They always provide one skill point and they are marked on a map of every location in specific parts of this guide. If you want to use a Shrine you need to use it with any member of your team. The reward will affect everyone.
Infected village/farm/pump station
These three locations will be located by Sue if you helped Agricultural center or in the radio if you helped Highpool. You have to pour to water containers the serum to complete the side quest named "Fix Sue's mistake and save three other communities from the Ag Center plague". In the village and on the farm, you find pod people, who explode at the moment of death, and also big bugs, which can poison the target, if successful.
In the village to the North of the Ag center, the sheriff who is imprisoned with his men, gives you a key to the building at the end of the road, after you save him, and the safe combination 62923779. Apart from that, it is worthwhile to search every location, because crates and caches abound there.
Wrecking Crew Stronghold
Sean Bergin will unlock this location for you in Highpool (even in destroyed Highpool). Beside a small group of Wrecking Crew you will find here few chests and a Shrine which will provide you one skill point.
This location is completely optional. You will find here a lot of strong robots which may reward you with a lot of experience points however better don't come here unprepared. You can also find here few storages, toaster with Amigo trousers (which are irrelevant in the later part of the game) and a robot named VAX who is not an NPC although he will follow your team and help you during battles.
One of the best methods to clear this location is to send a fast character ahead. Have them reach Vax, activate him and return to the party with him. Thanks to the firepower that the machine packs, difficulty level of the fight drops significantly. You only need to make sure that he is not wounded by the other machines.
This micro-location will be unlocked with the progress of the main plot. When you will have to get rad suits you will get to Rick's RV with Rick which you may release. You may find rad suits in the safe which has a key 733.
You will also find here a toaster with the faded photograph which you can deliver to Mon in Angel Oracle.
Beside the silo containing the nuclear missile (which you can disarm or send to the Temple of Titan) you can also find here the Sierra Madre plane in which Rick Baychowski located a treasure. You may help him and split the treasure or you can just take whole by yourself. You will also find here a Double Six tragedy report and AirMall Catalog in the toaster. You can deliver both these items to Flintlock from the Citadel.