Great hike! Bring some climbing rope to make it down (and back up) one 30 foot high section - ypu could donitnwithout ropes but some people might find it tough - or scary)
There are various options for a boat ride but go for a local one, not the more expensive touristic one. You can see a big chunk of the city from the river enjoying being a little bit away from it. The river is incredibly polluted though.