San Francisco's Transbay Transit Center threw its doors open Monday -- well, partway, in any case -- nine months and a week after cracks in structural steel shut down the brand-new $2.2 billion facility.

Starting at 6 a.m. this 1st day of July, the public once again had access to the center's entrance hall, at Mission Street between Fremont and First streets, and its 5.4-acre rooftop park for the first time since the facility's emergency shutdown last September.

The park, which will be open from 6 a.m. until 9 p.m. daily through Oct. 31, features stunning views of downtown and daily arts and recreational programs.

The views and programs will be much the same as before the closure, but one key piece of the park will be different.

The rooftop proved so popular in the six weeks it was open last year that its rubberized walkway surface wore out. Center officials said repairs were under warranty, and during the facility's closure the pathway was replaced with concrete.