That's it! I was there about 2 years ago as well (but obviously ~180 days before/after @pvpeacock). That's the National Palace where the King lives, and it was so weird to me that you can walk right through the gate, through the courtyards/gardens, right up to the wall of the building.
Kali Gandaki River, which combines with the Seti Gandaki and other rivers and seems to maybe become the Sapt (seven) Gandaki River which becomes the Gandak River in India. The Sept Gandaki is likely a big lake during flood season.