The
Goomburra section of the Main Range National Park has 2 great lookouts, with the Mount Castle Lookout lying at the end of Lookout Road providing views of the Mount Castle. The 1 km return walk is something well paired with the Winder Track walk as they start from the same car park.

Mt Castle seen from the lookout at Goomburra
Getting There
Not many people venture out to the Goomburra Section of the Main Range National Park because driving there is a little out of the way on the other side of the Main Range from Brisbane but it is well worth the trip, either as a day trip or for camping. The road there is easily accessible by conventional cars and there are 2 hikes accessible from the main road. But to get to the 4 other hikes, including Mount Castle, you need to drive up Lookout Road. This road is advertised as accessible by conventional vehicles but warning signs on the road advise against driving conventional vehicles on the road when it is wet. You do have a stony creek bed to drive over and, when we were there, some large potholes. So I would suggest at least an All Wheel Drive SUV for this road but you can see the conditions when you arrive and make your own call.

The Mt Castle Lookout Track starts at the end of Lookout Road in Goomburra
The Hike
To get to the lookout, you are walking in through beautiful rainforest, though the path is steeper than some others in the area, and the track is rough with plenty of roots across the track. I think that those roots make for nice photos and give the walk an otherworldly feel.

The track to Mt Castle Lookout is beautiful but a bit rough with lots of exposed roots
The lookout itself is narrow and the view is partly obscured by trees so you don't get to see the dramatic cliff and escarpment at the end of Mount Castle. You can still easily see how the mountain got its name, with castle like cliffs sitting over bluffs, so it is worth the stroll for these views. From the same starting point, you can walk down to the Walkers Camp on the Winder Track where you can see the part of Mount Castle obscured by the trees at the lookout.

The lookout is narrow with some of the view obscured by trees
Afterwards
Goomburra is well worth the drive out but there are not a lot of places to visit after your day hiking. The closest is the Maryvale Hotel or you have to wait until you cross back over the range to Aratula. I do like their steak and other $20 meal specials at the
Aratula Hotel so it is something to look forward to after a long day.

Steak & veggies meal deal at the Aratula Hotel
An alternative would be bringing your own tea, coffee and cake and having afternoon tea at Goomburra. There is a picnic area at the start of Lookout Road where there are picnic tables and wood burning barbecues for lunch, afternoon tea or even dinner.
Overall
Goomburra is one of the most beautiful national park areas in South East Queensland and well worth the effort to visit. You would want to do a combination of walks on a day trip, and have a weekend there to do all the walks. Mount Castle Lookout should be one of those walks visited and you can easily do it along with The Winder Track as they start from the same place.