Ultima 4 - Quest Of The Avatar

Go in the secret dungeon entrance at lord british's castle, and 
use four down spells, then use and exit spell.  You will 
appear next to dungeon hythloth. re-enter dungeon, explore and 
you will find a magic orb.  Use the magic orb, cast exit spell,
re-enter and repeat as wanted. (you need over 600 HP to do
this!) This gives you +5 intelligence, strength, and dexterity,
but takes OFF 600 hp each time!

Also, head west from dungeon hythloth to find the balloon.