Take the cable car up for sweeping views of Tbilisi and the Mtkvari river; the cable car typically operates from about 11:00–22:00, so mid-day views are great.
See the historic bathhouses and, if you wish, book a private room or a short soak — active roughly 08:00–23:00 and a quintessential Tbilisi experience.
Visit Sameba Cathedral (open ~07:00–19:00) for architecture and the Georgian National Museum (typically 10:00–18:00) for archaeology and national collections.
Short 30–40 minute drive from Tbilisi to the UNESCO town of Mtskheta; visit Jvari (offers panoramic views) — sites are typically open from around 9:00–18:00.
Either hike (~1.5–2 hours up) or take a 4x4 to the iconic Gergeti Trinity Church for unbeatable views of Mount Kazbek; the church area is open year-round (weather permitting).
Wander the charming ‘city of love’ with cobbled streets, craft shops and panoramic views of the Alazani Valley — town walls open during daylight hours.
Return to your hotel to collect luggage and enjoy a final coffee; allow plenty of time for transfer to Tbilisi International Airport (approx 20–40 minutes depending on traffic).