Allahabad enjoys the prestige of being one of the four holiest spots of India and thus host Maha Kumbh in every 12 years, Ardh Kumbh in every 6 years and Magh Mela once a year. The fact that it encompasses the confluence of the most sacred rivers of India- Ganga and Yamuna makes it all the more special.
It has its own culture of religious and literary overtones. You not only find a number of famous temples around the city of Allahabad but also places of historical significance like Anand Bhawan having produced 5 consecutive generations of able politicians of the nation, Akbar’s fort built following the common Mughal tradition of fort construction by riverside, Khusro Bagh housing some other Mughal remains. One can't miss the famous Allahabad museum!
You could take with you, religious paraphernalia, books on local literature and vintage handicrafts as mementos of the lovely city. From taking a dip in its holy waters , to enjoying a boat ride in Prayag, from throwing away coins to pay visit to Patalpuri temple, to roaming in Mughal era monuments, there are certain things unique to the city!