Laburnums are a common sight in streets, parks and gardens. It's easy to see why when the golden blaze of flowers is upon them. There are two species in the genus: L. anagyroides and L. alpinum both from central Europe where they also form a natural hybrid L. x watereri. The dangling flowers are characteristic of the Pea family Fabaceae (though Laburnums are poisonous!).
 I wasn't able to capture it in these photographs but numerous bumblebees were foraging among the flowers.