I finally managed to get closer to the Red Admiral (Vanessa Atalanta). This is a butterfly I don’t think I ever saw (noticed) until last summer, and it has been difficult getting close enough to it to get a good macro picture of it with its wings spread.
The wing span is 45-50 mm. The species is resident only in warmer areas, but migrates north in spring, and sometimes again in autumn. The caterpillar feeds on nettles, and the adult drinks from flowering plants like the Buddleja and overripe fruit. In northern Europe, it is one of the last butterflies to be seen before winter sets in. (Wikipedia)
Following the link to Buddleja, I also learned the name of those flowers in the park. It includes roughly 100 species. The generic name honours Reverend Adam Buddle (1662–1715), who was a botanist and a rector in Essex, England. Several species are popular garden plants. They are commonly known as butterfly bush due to their attractiveness to butterflies; they are also attractive to bees and moths.
I think the white ones below must be Buddleja too.