N
^ Index
/|\ -------
| D: door
| Su: stairs up to 1st level
s: secret door
-------
__________\\___/ \
| D______//___D |
Su|s__| _____ \ /
| | | | ---D--- ___
|___| | |__/ \____{ R }___/ \
|____ D_ D _____D { I } |
|_| |_{ V }___ |
{ E } \___/
R