Dinosaur print found between Greasy Grove and Snobby Shores. The print was surrounded by cameras so we don't know if the print was just a part of a movie set, if the cameras were for a news story, or if there really was a live dinosaur roaming about.
Supervillain Missile Base
Supervillain mountain lair or missile silo base was found in the west area of the map, just north of Snobby Shores. If you skydive in from the east, you won't be able to see the liar until you go around the mountain. The liar faces towards the water. As you land and enter through the garage doors, you will find some old cars, but as you walk towards the back of the garage, you end up in the middle of a missile launch facility. You will also find this place to contain hospital beds, science lab, and old computer stations.
One theory is that the supervillains could possibly use the nuclear missile to create chaos and panic. What better way to do this than to take out Tilted Towers with this nuclear weapon.
Secret Underground Room
Another secret room is located underground. Make your way to Salty Springs and go inside the Blue House. As you explore the house you will find the usual abandoned items such as cabinets and chairs but if you head down the stairs to the bottom floor, you will find a secret entrance to the underground floor containing a communications surveillance room.
Finally, the superhero base is located in a gorgeous mansion on the east side of the map near Lonely Lodge. The base is fully equipped with showers, server room, communications station, and everything a superhero would need to save the day. Take a look here.