I recommend anywhere you can keep an eye on your stuff. Cautionary tale: a famous photographer of my acquintance had a storage unit on Bainbridge Island. Full of furniture, paintings,file cabinets of photos...and some very pricey artwork. (Mark Tobey, Morris Graves, etc.) Well, one Friday I had lunch with her. On Saturday, another friend was in an antique store in Pioneer Square, and overheard a woman selling the owner a photo album of aforementioned famous photographer...claiming that they were from an estate sale.
As friend B. KNEW that artist A. was NOT deceased, he called me. I called the cops,and the artist. They did a sting operation at the antique store...and got back @90% of the stuff.
So how was the unit raided? Turns out the miscreants simply rented a unit at the same place, and with bolt cutters, cleaned out other units at their leisure. And since the owner didn't check on the unit often, it could have gone unoticed on for quite some time. It was only the sheerest luck (good for the photographer, bad for the crooks) that someone noticed .