How to get Cristina House
Once in Rome Termini Central Station, reach the exit next to Platform 1, on via Marsala. Just in front of you is Via Marghera: walk down it (three minutes, not more!) and then turn left on Viale Castro Pretorio. Cristina House is at number 64, the very first door on your left. Ring the bell "Cristina Hotel" and come up to the third floor!
About technical reason, check-is is done at Cristina Hotel, you will be carry to the reserved accommodation.