Abandoned Tunnels

As you slide towards the edge, you grab hold of a thick, slimy vine. You hold on to the vine as the piece of walkway slips off the edge with you on it. You fall for a few seconds before stopping fast.

You're alone dangling in the darkness by a single vine in the middle of nowhere. Your eyes adjust to the darkness and you see you've fallen a large distance. The vine was much longer than you initially judged. Ahead of you and a little below, you spot another, smaller pipe. If you swing back and forth on the vine, you might be able to make it.

Your arms begin to burn. It's now or never. Shifting your weight back and forth, you build up momentum, until your stomach churns from the swinging. 

You're almost there. One more swing. You fly backwards, then throw your entire body weight forwards. You're swinging towards the pipe, ready to let go when the vine snaps. Luckily, you have just enough momentum to go flying into the the pipe, completely uncontrolled. The foliage inside softens your impact as you crunch through layers of branches and vines. 

When you come to your senses, you see a long hole in the foliage, giving you a view back out into the large pipe. After a while, you struggle to your feet and continue forward.

Eventually, you reach an fork in the tunnel. One way angles upwards, while another remains level. The way upwards is more likely to bring you back to civilization. However, the tales of the lost treasures you may find if you continue to explore the deep sewers are tempting.