The Chattri Memorial is a monument for the memory of Indian soldiers who fought in France in the Great War. The link to Brighton is that it made great contributions to the war effort. They responded quickly to calls for arms, cared fro the wounded and more. The Royal Pavilion building was used as a hospital to accommodate more soldiers.
Every year a service is held at the monument in June - head to the website before turning up to make sure the service is scheduled to happen.
Otherwise, you can go for a walk up at the monument - it's completely free and offers wonderful views and a tranquil spot for meditation.
Concessions: Free entry