Undercliff (Isle of Wight)

Named after its position below the escarpment that backs this coastal section, its undulating terrain comprises a mix of rough pasture, secondary woodland, parkland, grounds of large isolated houses, and suburban development.

The Undercliff is a landslide complex in Cretaceous soft rocks, a bench of slipped clays and sands above a low sea-cliff, backed by higher (100 metres (330 ft)) Upper Greensand and Chalk cliffs.

[6] Interactions between the heavy chalk-based rocks of St. Boniface Down, the highest chalk downland on the Isle of Wight, and the softer rocks of the Undercliff below Ventnor means that subsequent erosion has caused Upper Ventnor, or Lowtherville, to gradually start moving towards the cliff edge, in a feature referred to residents as 'The Graben'.

[7] This rapid geological change in terrain is also responsible for necessitating the town's distinctive routes in and out of Ventnor, which feature panoramic views across Sandown Bay to the north-east, and the English Channel to the south.

[8] These developments included Steephill Castle, owned in the early 20th century by John Morgan Richards; the villa of Richards' novelist daughter Pearl Mary Teresa Craigie;[9] and houses built for the industrialist William Spindler in the 1880s during his attempt, cut short by his death, to develop St Lawrence as a town.

While the hospital was closed in 1964 and demolished in 1969, its grounds were redeveloped as the twenty-two-acre (8.9 ha) Ventnor Botanic Garden, which takes advantage of the same mild conditions to grow plants from worldwide Mediterranean habitats.

The area can be visited on foot by the Ventnor-Blackgang section of the Isle of Wight Coastal Path, and there are a number of scenic walks along and below the cliffs backing the Undercliff.