Escaping Ghast Statue

Java 1.12.2.

This map has a simple player home that somewhat resembles a wooden upside down pyramid. Is at: 39 70 246   

There is a haunting tunnel that leads to a overlook with sign and a Ghast Statue that is like a Ghast escaping into the overworld. Seems to be memorializing something that happened in the past.
The sign has a warning.

Tunnel start at: 590 91 241

Overlook with warning sign: 621 90 241

Escaping Ghast statue and nether portal: 660 95 218

Java 1.12.2