Originally Posted by mgood
For me it's The Bloodmage: The Metius Observatory using Isa's, especially if you have the Lockpick III skill (Unlock medium chests with no key). It's 4 battles (5 the first time thru) and 4 chests. With a 400% drop bag diamond and 5+ maxed out gold hexagons I've gotten up to 1 million in gold in about 5 minutes.
Usually I don't finish it though. I'll do 3 battles/3 chests, enter the cave to collect gold/ingredients and then return to the hideout.
+1... I think i have done literally HUNDREDS of obseratory runs.
I finish it always, as that will move the time (upgrade and build timers) about 3-4 hours each run.