The Vatican and St Peter's is the centre of Roman Catholicism, and St Peter's architectural matches its re-position. Its dome is one of the key features of the Rome skyline and it can be seen from many places across the city. Its grandeur is enhanced by the large Piazza that is in front on the Basilica, and is edged with a covered colonnade. At the centre of the piazza is a obelisk that is 13th century BCE and was moved to Rome in Nero's reign as emperor and later placed here.
The emperor Constantine had a church built here in around 330, but this was replaced as work began on the new basilica in 1506 and completed in 1623 with several architects, including Michelangelo being involved in its design. The result is a magnificent building that is considered the largest Church building in the world and has a capacity of over 60,000.
The interior of the building is elaborate and there is a sense of immense space. There are a great many statues and monuments, including Michelangelo's marble carved Pieta which is close to the entrance, but this has a protective glass shield.
There is free entrance into the basilica, however there are strictly enforced regulations about dress in that shoulders and knees must be cover. It is also possible to visit the tombs of the previous popes under the church, but I would probably skip it unless you are especially interested. Note if you do visit the grottoes the exit from this takes you outside the basilica, so make sure you explore the interior of St Peter's before you go. It is also possible to climb the dome for 5 euros, but there is often a long queue to do so, and so we skipped it.
The Chapel of the Blessed Sacrament, is open but it is as the sign states "Only those who wish to pray may enter" and thus it is a place of peace and stillness for many visiting Catholics. There are also regular masses said in St Peters several times a day - details can be found on the website www.vatican.va. And just for fun why not send a postcard from the Vatican City which is a separate country governed by the Pope. It has its own post office and you'll postcard will get a Vatican City postmark.
I'm not a Roman Catholic but I can appreciate St Peter's importance for millions of Catholics. But Saint Peter's is still an inspiring place that is well worth a visit no matter what your religious views are.