Great public buildings like the Customs House and the Four Courts were constructed, and private mansions like Powerscourt and Leinster House were built.
The Customs House, Four Courts, and Leinster House were built in Dublin, and Powerscourt was built in nearby Enniskerry, 
mnli hypothesis: The Customs House, Four Courts, and Leinster House were built in Dublin, and Powerscourt was built in nearby Enniskerry,  premise: Great public buildings like the Customs House and the Four Courts were constructed, and private mansions like Powerscourt and Leinster House were built.