Well, I did run out to the Elbbrücken station on the U4 line today.
It opened in Dec 2018.
I also went up to the viewing platform of the St. Nikolai Memorial.
The city’s 1968 Heinrich Hertz Tower (280 m/ 918 ft) has long been closed to visitors, but it might reopen in a few years.
Here’s the new end of the U4 line: the Elbbrücken station. It’s right by two steel truss bridges that go over the Elbe river: one for road traffic and one for rail.
There’s the U4 station in the distance on the left, then the steel bridge for cars*, and on the right edge, the train bridge. These are the Freihafenelbbrücke, constructed in 1926. (The Elbe river has a north and a south branch, with at least a dozen bridges). *And what are these go-carts doing on the road? Best I could tell, is that it is a group that did a jolly ride circuit around Hafencity. Shortly afterwards, all of them headed back from where they came from.
Here is a collage of images taken at different intervals, of the LED light boxes at the HafenCity Universität U-bahn station one stop down from the Elbbrücken station.
Here is the neo-Gothic St. Nikolai Memorial. At its completion in 1874 as St. Nikolai Kirche with a 147 m/ 482 ft spire, it was the tallest building in the world. Central Hamburg and its surroundings suffered terrible damage during WWII, though. In 1943 the church building was destroyed during Operation Gomorrah, but the spire escaped relatively unscathed. Today there is a plaza where the church building used to be, and a museum in the basement of the tower.
A gargoyle from St Nikolai looking over the Rathaus (city hall) from the spire’s viewing platform at 76 m/ 250 ft ..
.. and another view, revealing the rooftop of the Elbphilharmonie concert hall.