Edinburgh Castle Height: 122 Metres (400 Feet) Above Sea Level

Edinburgh Castle sits atop Castle Rock, a volcanic plug rising 122 metres (400 feet) above sea level — not "feet high" as a structure, but elevation.

Key Measurements

• Castle Rock summit: 122 m (400 ft) ASL
• Castle buildings: Add ~10-15 m atop rock
• Relative prominence: ~80 m (260 ft) above surrounding Princes Street/Old Town
• Highest point: Argyle Battery / Mons Meg area

Geological Context

Castle Rock is a dolerite volcanic plug — erosion-resistant core of a 340-million-year-old volcano. Glaciers carved surrounding softer sedimentary rock, leaving the plug as a crag-and-tail formation (Royal Mile = tail).

Comparison

• Arthur's Seat (Holyrood Park): 251 m (823 ft) — higher, extinct volcano
• Calton Hill: 103 m (338 ft)
• Ben Nevis (UK highest): 1,345 m (4,413 ft)

Why It Matters

Strategic elevation: defensible, visible, commanding Forth approaches. Human occupation since Iron Age (900 BCE). The height is the castle's reason for existence.