The 1.5km walk from the border to the town centre crosses the airport runway. A left turn off Corral Rd takes you through the pedestrian Landport Tunnel into Grand Casemates Sq. Alternatively, several local bus lines (adult/child/senior 60p/40p/30p) run from the border into town about every 15 minutes (every 30 minutes on Saturday and Sunday), until 9pm. Bus 9 goes to Market Pl, number 3 goes to Cathedral Sq and the lower cable-car station, and number 10 runs to Europort (stopping at Morrisons), then Reclamation Rd near the city centre.
All of Gibraltar can be covered on foot, and much of it (including the upper Rock) by car or motorcycle. You can also ascend, weather permitting, by the cable car (Red Sands Rd; adult one-way/return £6.50/8, child £4/4.50; every few min 9.30am-7.15pm, seven days; last cable down 7.45pm; except 1 Nov-31 Mar 9.30am-5.15pm, last cable down 5.45pm). For the Apes’ Den, disembark at the middle station.