In "Curse Of The Dead Ships Part 1", continue along past the panel with multiple of mines. Keep going to the next one. At the bottom of the cave, release Roadkill. He will find a secret passage leading down to two question marks.

In "Welcome To The Temple Part 1", when you get to the place with three rocks stacked up atop each other, simply take the left route. Follow it and then go down. Destroy the crawler and hit the wall on the side multiple times.