ToME WikiGetting There
The dungeon entrance is to the far south, somewhat to the west of Minas Anor. A difficulty getting to this dungeon is that you HAVE to cross either deep water or mountain chain. The mountain route is much preferable, but for that you need to have some equipment that makes mountain climbing possible. Such equipment is not common and luck is needed to get it.
You can also try to pass through the mountains using a small-scale/large-scale map trick. If you on the small-scale map find a valley of passable terrain at an accessible edge of on one of the three mountain squares bordering Dol Amroth in the east, you can enter it and press <, after which you can step on Dol Amroth's square on the large-scale map. Note that this depends on the random terrain generation and will either work well or not at all. Note also that the trick may not necessarily work in both directions.
It takes at least one or two squares of deep water to get to Dol Amroth via the ocean route. Anyone who has experienced deep sea ambushes knows the danger of this. To be safe, head over the deep water normally, without the map; then you can jump in and out of the mountains to avoid tough enemies.
Physical Aspects
Where it was once empty, the style is now a basic dungeon. The floors are normal and the walls are granite. There are no streamers. The levels are small as well, like the Maze. Dungeon towns and shafts are both availiable in Dol Amroth. The dungeon goes from level 25 to level 35.
Monsters
The main monster type in Dol Amroth is 'p', humans. Given the levels of the dungeon, the majority of these are various apprentices, men of Harad, Dunlendings, Wainriders, and others. There are also more 'P' giant humanoids that usual. Also, take note that enemies in Dol Amroth are levelled; not as extremely as Angband, but the difficulty increase is noticeable.
Guardian
The guardian of Dol Amroth is on level 35; and his name Prince Imrahil the Proud, a white 'p'. In Tolkien's books he was a 'goodie' so to speak, but here he has been corrupted. He is rather easy for warriors; his physical attacks do not hurt; however, he will summon humans, undead, demons and dragons. He drops a randart. He resists fire, cold, electricity, acid, nether and water.
Chatter
Resists water???
Is that an error? Or is it a monster-resist only unavailable to players?
This is fascinating.
FearofFours: It's a bit of a hack in the ToME source iirc, but yes monsters can resist water, although players cannot. Any water-borne monster resists water attacks for instance.
MassimilianoMarangio: RES_WATE is a normal race flag like NAZGUL or HURT_ROCK, also not available as player flags. The hack involves the immunity to water attacks for a single unique and 'E's with a name beginning with 'W' (Water elementals, but also e.g. Wind Elementals).