A large pond.

You walk out from the edge of the trees into the clearing and inspect whats in front of you.

It's a small, ornate pond, lined with bricks but seemed to have a muddy bottom. It was hard to tell since the "water" was very dark indeed, most likely liquid latex itself.

You decide to get a bit closer and walk up to the edge of the pond.

You gasp and jump pack a little as some bubbles well up from the center of the pond and break the surface, sending some weak ripples out that are quickly dissipated by the thick liquid.

"Definitely not water then," you muse.

You see something disturb the water again, a shapeless mass. It broke the surface but it was impossible to even begin to imagine what it could be.

Despite the potential danger, you continue to look at it.

Eventually, it swims up to the edge of the pond closest to you and breaks the surface.