Why go
Read the city from high ground before planning a route. Montjuïc shows the port and seafront together, while a view from the Collserola side reveals how the Eixample grid spreads between the older city and the hills. Those two perspectives make the neighbourhoods easier to place.
The full story
Barcelona occupies a coastal plain bounded by the Collserola range inland and the Llobregat and Besòs rivers on either side. The old centre sits nearer the sea; the Eixample extends across the flatter ground behind it. Montjuïc rises above the port, with its castle and a cluster of gardens, museums and sporting venues. On the other side, Tibidabo stands on the Collserola ridge. These are useful viewpoints, but neither belongs in a plan for a level stroll through the centre. The hills also explain why a route that looks compact on a map can demand more effort than one along the waterfront or across the Eixample. For a day that mixes old streets and open views, pair a central walk with one hill, allowing time for the ascent and descent.