In my new role as Director of Science Gallery London at King’s College London I often meet people at the site. The easiest place for this is at the bottom of the escalators at the base of the Shard. This is the exit from London Bridge Station for Guy’s Hospital and is at the junction of St Thomas St and Great Maze Pond. Here’s a map link (look for the green arrow). A reasonable postcode for searching would be SE1 9RL although it’s a short distance from there.