Appian Way

I did the è-bike tour by Top Bikes. There were 6 of us on the tour — a family with a 10 or so aged child, a couple, and me, a 68 year old retired nurse. Besides the Appian Way and the catacombs, the tour included Aqueduct Park and a refreshment stop at a sheep farm for cheese, wine and bread. The guide was congenial and informative, the biking was easy and I thoroughly enjoyed it. Feel free to PM me if you have questions.

The best time to visit the Appian Way is on a Sunday when the traffic is restricted. We did it on our own but a live guide always provides additional information. You cannot see the catacombs without a guide. And you can rent bikes for the Appian Way.

The Romans built amazing roads for their time. Many of the ancient roads have been paved over but still run the same path. That is true in Italy as well as England.

We did it on our own as well (on foot and from a further-out point back into Rome) but lots of folks like to do it a little quicker on bikes. You can rent them or take a tour.

If you do the Appia your own, the catacombs have entry fees and provide the mandatory guides. San Sebastiano is closed on Sundays but St. Callixtus is open (closed Wednesdays). I don't know as you need to do more than one or the other.

https://www.catacombe.roma.it/en/index.php

http://www.catacombe.org/uk_index.html

If you haven't found it yet, this is the park's website:
https://www.parcoappiaantica.it

There are some great maps/brochures you can download in advance from this page:
https://www.parcoappiaantica.it/home/risorse-e-utilita/download/category/1-flyer

I'll recommend downloading these three from that page:
Acquedotti_ eng_2014.pdf
AppiaAnticaeng2015.pdf. (we did this walk)
BrochureParcoeng2014.pdf.