fire giant village, missing map rooms

[byzanthia]

Room 74238 is:

Under a Waterfall (Water)
   Here falls the waterfall which springs from the western wall of the cave.
The water is freezing cold and it is very difficult not to drown under this
mass of falling liquid. The cave walls at the sides of the river are nearly
perpendicular and no way of escape can be seen except toward the east.
Exits: - East  - Down   [74238] 

On your map, its down exit leads to itself:

But that's incorrect. It leads to other rooms that are not on the mapper.

There are 3 east-west rooms right under the 3 water rooms your map does contain.

Under a Waterfall (Water)
   Here falls the waterfall which springs from the western wall of the cave.
The water is freezing cold and it is very difficult not to drown under this
mass of falling liquid. The cave walls at the sides of the river are nearly
perpendicular and no way of escape can be seen except toward the east.
Exits: - East  - Down   [74238] 

< 907h/907H 179v/180V P: std >
< |ss +|sk 2|ua +|ros +|sod +|cv +|cc +|wu +|nop +|ub +|ut +|hd +|dsd +|iw +|vip +| >     
d

Under the River
   This place is nothing else than turbid and freezing water. The stream of the
river is stronger here and hinders the movements. Sharp rocks cover almost
completely the river floor while long pale seaweeds wind around every moving
thing. The only way to exit before drowning is up to the surface.
Exits: - East  - Up     [74238] 
A copper coin. 
[5] Corpse of the carnivorous fish is lying here. 

< 907h/907H 179v/180V P: std >
< |ss +|sk 1|ua +|ros +|sod +|cv +|cc +|wu +|nop +|ub +|ut +|hd +|dsd +|iw +|vip +| >     
e

Under the River
   This place is nothing else than turbid and freezing water. The stream of the
river is stronger here and hinders the movements. Sharp rocks cover almost
completely the river floor while long pale seaweeds wind around every moving
thing. The only way to exit before drowning is up to the surface.
Exits: - East  - West  - Up            [74237] 
Corpse of the carnivorous fish is lying here. 

< 907h/907H 178v/180V P: std >
< |ss +|sk 1|ua +|ros +|sod +|cv +|cc +|wu +|nop +|ub +|ut +|hd +|dsd +|iw +|vip +| >     
e

Under the River
   This place is nothing else than turbid and freezing water. The stream of the
river is stronger here and hinders the movements. Sharp rocks cover almost
completely the river floor while long pale seaweeds wind around every moving
thing. The only way to exit before drowning is up to the surface.
Exits: - West  - Up     [74235] 
Corpse of the carnivorous fish is lying here. 

< 907h/907H 178v/180V P: std >
< |ss +|sk 1|ua +|ros +|sod +|cv +|cc +|wu +|nop +|ub +|ut +|hd +|dsd +|iw +|vip +| >     
u

On a Freezing River (Water)
   The river runs from east to west through the vast cave and continues in the
narrow gorge that starts east of here. Its dark freezing water is very turbid
and prevents seeing through it. Here the stream is not strong and it is
possible to go up the river toward the west or to reach each of its shores.
Exits: - North - South - West          [74235] 
Corpse of the carnivorous fish is lying here. 

[byzanthia]

Also, if you go to room 74228 and type "push statue":

The Shrine to Annam
   This large room is consecrated to the greatest God of the giant races, the
fearsome Annam. His blue marble statue rises in the center of the shrine
surrounded by several benches upon which some fire giants pray silently. There
are six stone pillars on each side of the room, on them are hanged some small
lanterns which provide a soft light. A huge marble altar leans on the southern
wall, upon it a small brass brazier diffuses smokes of incense. The central
tunnel is accessible through an opening in the northern wall while the shrine
of Kossuth is south from here.
Exits: - North - South  [74228] 
A blue marble statue portraying Annam stands in the center of the room. 
A fire giant commoner is here, praying to his God.
A fire giant commoner is here, praying to his God.
The fire giant shaman stands here, praying to his God.

< 907h/907H 163v/180V P: std >
< |ss +|sk +|ua +|ros +|sod +|cv +|cc +|wu +|nop +|ub +|ut +|hd +|dsd +|iw +|vip +| >     
push statue
You hear a rumbling sound in the distance.

Then run back to 74238, a new exit has opened to the up. There are a few rooms up there that you also missed:

A Secret Cavity Behind the Waterfall
   This small cavity seems natural although the walls are pretty regular
without any evident roughness. The floor is damp and slippery and walking has
to be slow and prudent to avoid falling. A huge stone door is on the western
wall, several ward runes are carved upon it. A strange chilly sensation is
clearly noticeable, as if this place had a curse upon it.
Exits: - West # - Down   [74238] 

< 907h/907H 179v/180V P: std >
< |ss +|sk +|ua +|ros +|sod +|cv +|cc +|wu +|nop +|ub +|ut +|hd +|dsd +|iw +|vip +| >     
unlock door w
*Click*

< 907h/907H 180v/180V P: std >
< |ss +|sk +|ua +|ros +|sod +|cv +|cc +|wu +|nop +|ub +|ut +|hd +|dsd +|iw +|vip +| >     
open door w
You open the door.

< 907h/907H 180v/180V P: std >
< |ss +|sk +|ua +|ros +|sod +|cv +|cc +|wu +|nop +|ub +|ut +|hd +|dsd +|iw +|vip +| >     
w

The Tomb of the Duergar King
   This room has a high ceiling and a stone floor polished mirror-smooth. In
the center of its western wall, the floor climbs up four steps to a raised
dais. On the dais there is an obsidian sarcophagus and a granite statue
depicting a stern-faced, bearded duergar in plate armor, axe raised as if to
kill enemies. There's no source of light in this room except for the sparkling
of the runes carved on the stone door to the east.
Exits: - East          [74238] 
An obsidian sarcophagus leans here against a wall. 
A spectre of a duergar warrior flows in the air here.