Sant’Anna a Ripa was an 18th century guild church, now demolished, just to the west of the junction of the Clivo di Rocca Savella and Via Santa Maria in Cosmedin, below the Aventine. This is in the rione Ripa.
The dedication was to St Anne, mother of Our Lady.
Before 1745 it was known as Sant'Anna de Marmorata, although the present Marmorata district is at the other end of the Aventine next to Testaccio. It is listed in the Catalogue of Turin in the 14th century, and was allegedly founded by the palafrenieri or grooms of the Papal court in the 13th century. If so, it is an ancestor of Sant'Anna dei Palafrenieri at the Vatican.
In the 14th century it had a small monastery attached for four monks, hence was referred to as an eremitorio or hermitage. In the Middle Ages the Clivo was the main route to the monasteries on the Aventine, and this little complex guarded its entrance.
Certain sources claim that the original dedication was to Our Lady, and that it was changed when it became a guild church -which is contrary to the palafrenieri theory mentioned above.
In 1745 it was taken over by the Calzettari or guild of stocking-makers, which apparently completely rebuilt it. Apparently it had a hermit in residence in the mid 19th century.
The church was demolished in the late 19th century (the exact date seems unknown), and later replaced with a modern building having a relief of St Anne on its frontage. Some modern writers claim that it was demolished in the 20th century. Did nobody notice at the time?
The church was right on the corner between the Clivo and the road. The modern building there now has a terrace in front of a pedimented façade, and the church occupied the right hand side of this. The short section of wall right on the corner is the site of the entrance.
The right hand wall of the church was on the roadside in the 18th century. It was a simple rectangle, with four pilasters on the side walls supporting the roofline.
Descriptions of the interior are lacking.
Achille Pinelli painted a watercolour in 1834, which he entitled San Salvatore de Marmorata. There is a problem with this, as the sources claim that a church of this name was demolished in the 15th century and was originally located near to Sant'Anna. The painting is reproduced on a Flickr gallery; see link below. The author of the gallery identifies this church with Sant'Anna. It is not; it shows San Salvatore de Porta. The give-away is the Pyramid of Cestius appearing on the extreme right.
There also seems to be a long-standing confusion with San Lazzaro alla Marmorata. Several authors mention that the church was near the Arco della Salara. This is not the same as the present Arco di San Lazzaro, next to the Via Marmorata. The road which the present Lungotevere Aventino replaced, the Via della Salara, narrowed very abruptly just south-west of Sant'Anna, and passed under an archway. An old photo exists, and you can just about see the church through the archway in it.
Finally, there is a confusion with Sant'Aniano dei Ciabattini in published sources.
De Alvariis gallery on Flickr (This is not Sant'Anna).