Happy new year! I thought a sunset/sunrise would be fitting for the theme. Version 1 of the World's Edge sunset/sunrise icon. Version 2 has a different color style [link]
There's a cliff near Lavender, just far enough for the town to be out of sight. When standing on that cliff, not a hint of civilization or life can be seen. Ahead there's nothing but the endless ocean, as if it was the very edge of the world.
This place will appear in a later chapter of Don't Give Me Diamonds [link]
It is a fan made location. Here's a bigger picture of this place: [link]
Pokemon (c) Nintendo