This is an illustration of why apostrophes are important! It is actually named after Roberts, rather than Robert (and is thus "The Roberts House", not "The Robert's House").
Roberts was Lord Roberts, a great British soldier of the C19th, who was involved in conflicts in India and South Africa, during the latter of which he was instrumental in the sue of concentration camps by the British. He was a big enough hero of the empire to be one of only two non royals to lie in state in Westminster Hall, prior to his funeral (the other was Churchill). In many ways, not an obvious person to be commemorated in an Irish zoo.
