From the south on the M6/M74 take the Glasgow south route follow airport signs plus heading for Erskine bridge then onto the A82 heading for Crainlarich then at Tyndrum take the A85 for Oban. (Or for Trossachs route head for Stirling on the M73/A80. Take the M9 for Perth, exiting for Stirling at junction 10, taking A84 heading for Crianlarich, finally on to the A85 to Oban).
From Oban take the main A816 South road - signposted for Lochgilphead and Campbeltown - for 2 miles, then turn right onto road signposted for Lerags, continue down a single track road for 1 mile when you will see a Lagnakeil sign pointing you further down the glen. After a further half mile only you will see a sign saying “Welcome to Lagnakeil”. Turn right into Lagnakeil, then drive right up the hill to the farmhouse reception.
You can also fly to Glasgow or Edinburgh and hire a car at the airport or catch the train from Glasgow Queen Street direct to Oban and hire a car in Oban. Or if you would rather not drive at all, you can bring bikes on the train free of charge (you need to pre-book though) then Lagnakeil is an easy ride from Oban.