In the struggle that is developers getting you to play their game - and their game only - every single day, knowing there are secret locations to seek out is one of the best reasons going.
With completion rates at an all-time low, game lengths an all-time high and general world size reaching into the hundreds of square kilometres and beyond, if you're going to wander off the beaten path, it needs to be for something special. Times have changed since the cheat codes and plug-in cartridge days of the 90s and early 2000s, and many devs have started hiding their levels out of bounds entirely.
Now, we actually did a version of this list in August 2018, but that only opened the floodgates as to all the tucked-away areas across gaming, that you guys have found.
From iconic English cities to out of bounds areas where you can fall forever, there are TONS of secret areas worth digging out your old games to revisit.