jollyrog, thanks for the detailed suggestions
as for the rules on landing and EGLC - yeah I read in the AIP that single engine use prohibited, but then again it would be veeeery strange if they would prohibit use in case of an emergency
but the EGLC landing is irrelevant to my question, the main question was about sightseeing. thanks for the heads up, indeed I guess it would depend on the traffic and approach direction at EGLC.