Lindsay Lohan Rehab Facility -- Surrounded by Temptation

8:00 AM PDT: Lindsay's attorney Mark Heller is telling various tabloids that no decision has been made on which rehab facility Lindsay will enter.

Sources connected to the situation tell TMZ ... Heller is not telling the truth. A decision HAS been made, and Lindsay's going to Seafield.

Lindsay Lohan will do rehab 15 minutes from the hottest summer club scene in the country ... problem is, if she tries to escape she's going directly to jail.

Law enforcement sources tell TMZ ... Lindsay's lawyer and prosecutors have agreed on a facility where she'll do her 90 days of rehab. It's called Seafield Center in Westhampton Beach, NY.

Seafield is NOT a lockdown facility -- something prosecutors and the judge required. But we broke the story ... there's no such thing as a true lockdown rehab joint where people are essentially held hostage.

We've learned prosecutors have modified the plea bargain and have agreed on Seafield. It's an inpatient facility where patients are not supposed to leave, but no one can stop them if they walk out the door.

But here's the reason why Seafield was chosen -- It has 24-hour staff guarding the doors, as well as surveillance cameras and walls. If Lindsay tries to leave, she can't be stopped, but someone would see her and notify authorities. That would trigger a probation violation and the judge would almost certainly throw her butt in jail.

As for the cost ... $4,025 a week. Grand total for 90 days -- $51,750.

One problem. We've learned the facility is not designed for a 90-day stay. The limit is 28 days. An admissions person told TMZ ... they've never had anyone there longer for one stay. But we've learned the administrator has told prosecutors he'd stylize a 90-day program just for Lindsay

One final thing. There are lots of rules. No tobacco, no cell phone, and you can't dress like a slut ...