The biggest obstacle to those who would like to recycle Mellon Arena is not dreams, but reality.

We say recycle, not preserve, because no one is actually proposing that the five-decade-old facility, despite claims to its historic significance, be saved as an auditorium right next to the state-of-the-art Consol Energy Center. As a civic center, Mellon Arena is old and outmoded. Finished.

So the best the arena "preservationists" can do is call for hollowing out the seats and tucking a new hotel, park, skating rink -- anything -- under the retractable dome. Assuming it still retracts.

The fact that no developer has stepped forward to embrace the idea with financing and risk-taking is the idea's chief obstacle. Despite all the hotels that have been built in Pittsburgh in the last two years, when it was universally known that the arena was being replaced, no builder or speculator showed interest in reaping the dollars that would surely rain down from the arena dome. For good reason. That's a rain that will not fall.

Pittsburgh will be well served by a development plan that restores the street grid of the lower Hill District through the arena site. Put houses and businesses where asphalt used to be and memories live on. The reality is the arena had a fine run. It's time to let it go.

Cartoonist Rob Rogers does "Rob's Rough," an early look at his work and his creative process, exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.