Game maps and the terrain they represent can be gorgeous works of art. In more ways than one. Besides being physically impressive or beautifully illustrated in exquisite detail, they can embody cleverness of design that it takes time and understanding to really appreciate.
A dungeon full of monsters and traps can present such an intricate and meticulously crafted puzzle that it forces the act of negotiating it successfully to be a heroic endeavour, for any lesser attempt would be doomed to failure. By forcing the players to surpass and overcome their own limitations simply in order to survive, you generate the stuff of legend.
This explains the eternal appeal of such a horrific deathtrap as the Tomb of Horrors, which we have mentioned before. It's not merely a place where PCs go to die - it's a masterpiece of the dungeon designer's art, a magnum opus of carefully crafted detail, a timeless classic that embodies the essence of what it means to create a challenging and, yes, ultimately, rewarding adventuring experience.
At least from the point of view of those GMs who run it. When you're looking at such a thing from the player's side, it simply sucks.
Padmé: Hey, Yoda, come and get me. We have a fight to get to!
GM: You can't hear her—
Padmé: HEY YODA!!
GM: —she's out in the desert and you're commanding the troops.
Yoda: I use my Force powers!
GM: Oh... you're playing a powerful Jedi Master. I keep losing track.
R2-D2: I could pick Padmé up. I should be back in the ship by now.
GM: You said you were going through the factory, right? Let me see the map you made.
R2-D2: Er... O-kaay.
Yoda: Captain, the fight we must join. Artoo will get Padmé and Master Windu will wipe up the crumbs here.
GM: Wow. Frankly I don't see how anything could get through this...