Rick's top picks for Seville are here: https://www.ricksteves.com/europe/spain/sevilla. Click on At a Glance.
There's much more, depending on your interests; these are in no particular order and don't include Rick's suggestions:
Casa de Pilatos, Plaza de Pilatos 1, NE of Alcazar and cathedral: “blissful secret garden” and tiled salons. “Gem of Andalucian architecture”. Patio Principal Mudejar with azulejos and intricate plasterwork. Mudejar ceilings in some upper rooms, but much is high Renaissance; art mostly mediocre.
Ayuntamiento (Town Hall), Plaza Nueva 1: 16C. Ornate facade and interior. East facade best example of Plateresque style in Andalucia. Sculpted ceilings in vestibule and lower Casa Consistorial (Velazquez ptg). Gold coffered ceiling in upper Casa Consistorial (Zurbaran and Valdes Leal).
Aqueduct, Callejon del Agua: Also flower-filled patios here.
Hotel Alfonso XIII, Calle San Fernando 2: Neo-Mudejar decor. Regionalista style, with wrought iron, tiles, ornate brickwork. Gorgeous patio. Bars and restaurants open to public.
Jardines de Murillo: formal gardens.
Calle Guzman el Bueno: Classic town mansions with courtyards.
Plaza del Triunfo: beautiful.
Hospital de los Venerables, Plaza de los Venerable 8. Baroque. Small art exhibition, tiered central patio and 17C frescoes in chapel.
Plaza de Toros de la Maestranza: 18C. White and ochre Baroque facade.
Torre del Oro: Moorish. Departure point for boat trips and tours.
Iglesia de la Magdalena: Large Baroque Church, early 18C, restored. Capilla de la Quinta Angustia is Mudejar. W. front colorful belfry.
Archivo de Indias, Avenida Constitucion: Historical museum.
Metropol Parasol, Plaza de la Encarnacion (Las Setas): modern, mushroom-like wooden structure; excellent views from skywalks and archaeological museum in basement.
Palacio de las Duenas, Calle Duenas 5: 15C Renaissance with Mudejar and Gothic influences. Lovely courtyards and gardens. One of city’s most beautiful palaces; can visit ground floor.
Iglesia San Juan de la Palma: Small Mudejar church. Brick belfry added 1788.
Iglesia de San Pedro, Plaza San Pedro: Mixed styles from Mudejar wooden ceiling (poorly lit) to modern tiles on facade. One chapel has exquisite geometric brick vault. May be open only for mass.
Iglesia de Santa Catalina, Plaza Ponce de Leon: Mudejar tower and apse. Closed for restoration as of 2019.
San Roman: 19C Mudejar-Gothic church with fine coffered ceiling.
Palacio de los Marqueses de la Algaba, Plaza Calderón de la Barca: Interpretation Center of Mudéjar Art (small) puts the style into historical context and introduces city’s main Mudéjar sites.
Antiquarium, Plaza de Encarnacion: Archaeological Museum.
Basilica de Jesus del Gran Poder, Plaza San Lorenzo 13.
Iglesia de San Luis de los Franceses, Calle San Luis 37.
Convento de Santa Clara, entry on Calle Becas: Mudejar/Renaissance. Used for special exhibitions (pricey).
Feria Market, Plaza Calderon de la Barca: Picturesque; one of city’s oldest. Two light-flooded buildings. Mon-Sat.
Out of room. See following post.