I have no idea whether this Park Hotel is part of the same chain of Park Hotels elsewhere in Iran, but compared to the very nice one I stayed in in Shiraz, this one is not so good.
This hotel is a 20-minute walk east of the town centre. There's not much to do in the area anyway so you're not missing much by staying here.
The hotel is ok for a night or two - it's very basic, with a fairly nice lobby. It's by the main road in Azadi Square (east of the centre but not too far from the main bus terminal for Tehran) and can be very noisy even at night - too many large trucks!. Rooms are being refurbished on the second floor, and the first floor looks pretty nice after being done up.
However, as the first floor was fully-booked by a tour-group, I had to stay on the third floor which looks very dated. The room wasn't too small, but it wasn't terribly nice - there was a fridge (noisy), a TV (basic channels), western-style toilet and hot water. Shower was overhead and although it took a while to hot up, it was quite nice. A bit of a problem with flushing the toilet but one night is tolerable. There's no in-room safe so you have to hand possessions over the the reception. There's also a lift so heavy luggage is no problem.
Reception was fairly helpful but there were one of two language problems. Breakfast is not included in the price of about $20 for a single room, and costs about $4. I didn't have it.
Hotel Sadi down the road is very similar so of the two, I'd choose Park Hotel provided they give you a new room on the first floor. Otherwise, the two hotels are much of the sameness.