Where is the well-looking thing in solaceon town diamond?

You're likely referring to the "Well-Looking Thing" in Solaceon Town in Pokémon Diamond. This refers to Dawn's (or Lucas's) rival who is considered very attractive.

However, there is no specific location where you can find them in the town. They are a character you encounter during the story, not a stationary NPC.

To find Dawn/Lucas's rival:

1. Progress through the game: You'll encounter them at various points in the story, usually at Pokémon Centers or in important locations.

2. Pay attention to the story: The game will guide you to the locations where you can interact with them.

Remember, "Well-Looking Thing" is a playful nickname for your rival and not an actual in-game item or location.