Tharwa is a great idea for a day out and there is a lot to see in a small area. You could consider riding there south through Canberra, or if you are keen then try the loop ride from Stromlo Forest Park south through the suburbs to Tharwa, where you cross the Murrumbidgee River and return to Stromlo Forest Park on the other side of the river via Tidbinbilla Nature Reserve and Cotter.
A sunset ride on Stockdill Drive is one of the best things you can do. The road suddenly ends, which discourages traffic. Apart from a farm or two, nobody lives there. You will pass the Woodstock Nature Reserve and Shepherd Lookout along the way – a lot to see in just 3.4 km.
Mount Stromlo Forest is a large reserve on the slopes of Mount Stromlo. West of the mountain, many creeks run off undulating hills into the Murrumbidgee River, and have cut into the clay to form deep creek beds.
You are permitted to ride Mount Stromlo Forest on the management trails. This is generally true in all Canberra nature reserves with few exceptions. Mount Stromlo is famous for the network of “single tracks” on the east side at Stromlo Forest Park. These trails are specifically meant for mountain bikes but do not be surprised if you find walkers there too.