Outside the metal door is the fabled Sphinx, looking a little worse for wear in this pixelated 1999 incarnation.
There are also deep pits on both sides of the door. Approach the pit to the right (north). Take a carefully angled running jump to the flat ledge on the left (west) side of the pit. (Or slide down the slope onto the ledge just below the rim of the pit. Then jump over to the ledge on the left.)
From there take a running jump to grab the flat spot on the northeast rim of the pit.
Pull up and continue forward (north).
There's a roll-down door ahead on the right, but you can't open it yet. Proceed to the edge of the next pit.
Take a standing jump down to the ledge with the large medipack.
When you land, another guy in blue robes appears on the north rim of the pit. Kill him, then pick up the medipack.
Now take a running jump to the ledge in the northeast corner of the pit (below where the bad guy just stood).
Climb/jump out of the pit. Approach the blue door, press Action to kick it open, then enter the building.