The C105 comprises two distinct pieces of road in the centre of Lerwick. The first is the C105-010, which is a continuation of the C104, Market Street. It follows Hillhead, which is one-way southbound at the northern end, but does not include the complimentary Lower Hillhead. This part of the route comes to an end on the A969, Clairmont Place.
The rest of the C105 lies to the east. The first section is the C105-150, which follows Haldane Place and Queens Lane from the A969, Church Road, west then north to meet Commercial Street, the C106. However, none of this route seems to be wide enough for vehicles to pass along, except the southern end of Queens Lane, which is part of a car park. A little to the east of the junction of Queens Lane and Commercial Street, the C105 reappears once more, running east along Commercial Street from the A969 to the junction with Stout's Lane. This is designated the C105-160, and bizzarely it is sandwiched between two separate pieces of the C106, which follows Commercial Street at either end. There seems to be little logic to any of this.