Ben A'an is a 5 minute drive around the corner from Loch Katrine. There is a dedicated carpark and the path through the forest is actually signposted from the roadside.
The hill itself provides an easy walk, suitable for families with young children or anyone else. Winding up through the forest, following a stream for much of the way, the walking is easy and not too steep.
The final stretch to the top of the hill is, however, twice as steep but this starts off as a "man-made staircase" in an attempt to combat erosion. Just before the steep section is a viewpoint where you can look out over the Loch and watch the activity around it and on the water. Behind the loch lies Ben Venue...
Routefinding is incredibly straightforward in good conditions and for experienced walkers there are almost no difficulties. The path is extremely popular and will be busy almost every weekend and almost certainly sees plenty traffic on weekdays during the summer.
That said you should still take a good map/compass and know how to use them properly"
Follow the instructions for Loch Katrine and follow the road for 0.5km rather than turning off for the Loch.
The entire walk (straight up and straight down) can be done in about 1.5 hours if you are relatively fit. The hill is only 460m in height. Good walking boots are recommended, as are binoculars, camera and waterproofs.
Insect repellant is essential in the summer since the path goes through the forest - if you're quick, perhaps you'll escape unbitten!