I hadn't really registered the presence of these jetties on the South Bank, still less that they're publicly accessible!
The northern bank of the Thames was regularised by the construction of Sir Joseph Bazalgette's Victoria Embankment which, in addition to carrying sewerage mains, narrowed the channel to improve discharge. Boats can therefore moor directly against the vertical northern wall (tide permitting), but jetties are evidently needed on the more-naturally sloping South Bank.
This one stands at Gabriel's Wharf, between the eastern end of the South Bank's tree-lined 'promenade' and the landmark OXO Tower.
Behind is the second Blackfriars Bridge; the first was an Italianate-style toll bridge spanning 303 m in nine semi-elliptical stone arches, built for the Corporation of the City of London and opened in 1769 as the third bridge across the Thames within built-up London, following London Bridge (also owned by the Corporation) and Westminster Bridge (the rival!). Originally named the 'William Pitt Bridge' after the Prime Minister, it soon became better known for its location, near the site of a Dominican (Black Friars) priory. More specifically, the mouth of the River Fleet had left a gap in the northern wharfside, so the Bridge was built over it rather than disrupt neighbouring commerce. The Fleet still emerges from a culvert beneath the Bridge.
Much repaired, the faulty bridge was finally replaced entirely in 1869, as part of the aforementioned Victoria Embankment development. This one, by Joseph Cubitt and now Grade II Listed, spans 281 m on five wrought iron arches. Initially 21 m wide, it was extended to 32 m in 1907-10 to accommodate increasing traffic. Like London Bridge, the full length of Blackfriars Bridge remains within the jurisdiction of the City.
Beyond the bridge, directly behind the end of the jetty, one can just see the pillars of the first Blackfriars Railway Bridge, which was also designed by Cubitt and slightly predates the road bridge, having opened in 1864. However, with changed traffic priorities and rolling stock, Cubitt's bridge became obsolete, and the the adjacent St Paul's Railway Bridge (1886, by John Wolfe-Barry and Henry Marc Brunel - the sons of architect Sir Charles Barry and engineer Isambard Kingdom Brunel) inherited the 'Blackfriars' name in 1937. The original's deck was finally removed in 1985, though the easternmost pillars now partially support the modern London Blackfriars station, which extends right across the Thames beneath a roof covered by 4,400 photovoltaic solar panels, meeting half the station's energy requirements and making this the world's largest (of three...) solar bridges.
Charles Bell Birch's 1896 bronze statue of Queen Victoria, now Grade II Listed, stands at the north end of Blackfriars Bridge. Behind, the brown-and-white commercial building is Blackfriars House, designed by Frank Troup, built 1913-16 and now Grade II Listed.
Even if it wasn't being beautifully highlighted by the late afternoon light, I suspect you might notice St Paul's Cathedral, on Ludgate Hill at the heart of the City of London. A church dedicated to St. Paul has occupied the site since 604, but Sir Christopher Wren's English Baroque masterpiece, the fourth cathedral on the site, was built after the 1666 Great Fire of London, being (officially) completed in 1711. The tallest building in London until 1962, St Paul's remains the second largest (by volume) church in the UK, with one of the highest (at 111 m tall) and 'most perfect' domes in the world. Aside from being a true icon of London, it's the nearest the UK has to a 'national' church, having been the venue of key funerals, weddings and commemorations of British history.
To the right of St Paul's stands the green-roofed Faraday Building, designed by A.R. Myers and built in 1932 as a purpose-built home for London's first telephone exchange (which had expanded rapidly since opening in 1902). It occupies the site of 'Doctors' Commons', the obsolete "College of Doctors of Law exercent in the Ecclesiastical and Admiralty Courts" and, by obscuring the riverside view of St Paul's, was the inspiration of legislation restricting the height of subsequent development around the cathedral.
Evidently, the statute doesn't apply further from St Paul's; the building visible behind the Faraday Building, for example, is the Broadgate Tower, a 165 m, 33-storey 'skyscraper', the 12th tallest in London (4th in the City of London), over the entrance to Liverpool Street station at the northeastern corner of the City.
The 13th tallest building happens to be visible on the left, ~2 km from here, behind the north-western tower of St Paul's. Originally built in 1967 as Britannic House, the headquarters of British Petroleum (BP), at 122m (35 storeys) it was the first building in the City to exceed the height of St Paul's; refurbishment in 2000 added a further 5 m and the new name 'CityPoint'.
At the extreme left is the 82 m, 18-storey Alban Gate, at 125 London Wall. Like Embankment Place, above Charing Cross station, it was designed by Sir Terry Farrell (that arched roof is a distinctive similarity) and built 1990-92.